Polyethylene Terephthalate (PET) is produced from esterification of mono ethylene glycol (MEG) with terephthalic acid (TPA), or from transesterification of mono ethylene glycol (MEG) with dimethyl terephthalate (DMT). But, what would happen if you substituted 2-methyl-1,3-propanediol (MPO) for mono ethylene glycol (MEG) in the PET polymerization process?